/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.tsfile.read.query.dataset;

import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.read.common.Path;
import org.apache.iotdb.tsfile.read.common.RowRecord;
import org.apache.iotdb.tsfile.read.query.timegenerator.TimeGenerator;
import org.apache.iotdb.tsfile.read.reader.series.FileSeriesReaderByTimestamp;
import org.apache.iotdb.tsfile.utils.TsPrimitiveType;

import java.io.IOException;
import java.util.List;

/**
 * query processing: (1) generate time by series that has filter (2) get value of series that does
 * not have filter (3) construct RowRecord.
 */
public class DataSetWithTimeGenerator extends QueryDataSet {

    private TimeGenerator timeGenerator;
    private List<FileSeriesReaderByTimestamp> readers;
    private List<Boolean> cached;

    /**
     * constructor of DataSetWithTimeGenerator.
     *
     * @param paths         paths in List structure
     * @param cached        cached boolean in List(boolean) structure
     * @param dataTypes     TSDataTypes in List structure
     * @param timeGenerator TimeGenerator object
     * @param readers       readers in List(FileSeriesReaderByTimestamp) structure
     */
    public DataSetWithTimeGenerator(
            List<Path> paths,
            List<Boolean> cached,
            List<TSDataType> dataTypes,
            TimeGenerator timeGenerator,
            List<FileSeriesReaderByTimestamp> readers) {
        super(paths, dataTypes);
        this.cached = cached;
        this.timeGenerator = timeGenerator;
        this.readers = readers;
    }

    @Override
    public boolean hasNextWithoutConstraint() throws IOException {
        return timeGenerator.hasNext();
    }

    @Override
    public RowRecord nextWithoutConstraint() throws IOException {
        long timestamp = timeGenerator.next();
        RowRecord rowRecord = new RowRecord(timestamp);

        for (int i = 0; i < paths.size(); i++) {

            // get value from readers in time generator
            if (cached.get(i)) {
                Object value = timeGenerator.getValue(paths.get(i));
                if (dataTypes.get(i) == TSDataType.VECTOR) {
                    TsPrimitiveType v = ((TsPrimitiveType[]) value)[0];
                    rowRecord.addField(v.getValue(), v.getDataType());
                } else {
                    rowRecord.addField(value, dataTypes.get(i));
                }
                continue;
            }

            // get value from series reader without filter
            FileSeriesReaderByTimestamp fileSeriesReaderByTimestamp = readers.get(i);
            Object value = fileSeriesReaderByTimestamp.getValueInTimestamp(timestamp);
            if (dataTypes.get(i) == TSDataType.VECTOR) {
                TsPrimitiveType v = ((TsPrimitiveType[]) value)[0];
                rowRecord.addField(v.getValue(), v.getDataType());
            } else {
                rowRecord.addField(value, dataTypes.get(i));
            }
        }

        return rowRecord;
    }
}
